Apparatus for making solder connections



P 1943- w, E. INGERSON 2,328,982

APPARATUS FOR MAKING SOLDER CONNECTIONS Original Filed May 8, 1941 4 Sheets-Sheet 1 MI l/EN TOR WE. INGERSON ATTORNEY P 1943- w. E. INGERSON 2,328,982

APPARATUS FOR MAKING SOLDER CONNECTIONS Original Filed May 8, 1941 4 Sheets-Sheet 2 FIG? lNl/E/VTOR A32 INGERSON A T TORNE V Sept 1943- I w. E. INGERSON 2,328,982

APPARATUS FOR MAKING SOLDER CONNECTIONS Original Filed May 8, 1941 4 Sheets-Sheet 3 lNl/E/VTOR WE /NGE R5 ON 5% flack (OM 1 A T TORNEV Sept. 7, 1943. w. E. INGERSON APPARATUS FOR MAKING SOLDER CONNECTIONS Original Filed May 8," 1941 4 Sheets-Sheet 4 N M 0 b9 R5 I} \T O 4 Qi m vb Q I m9 c m; g 325 m 0 M I W W a 74/??? W m WW0 A T TORNEV Patented Sept. 7, 1943 APPARATUS FOR MAKING SOLDER CONNECTIONS William E. Ingerson, North Plainficld, N. J., as-

signer to Bell Telephone Laboratories, Incorporated, New York, N. vY., a corporation of New York Original application May 8, 1941, Serial No.

392,505, new Patent No. 2,308,686, slated January 19, 1943.

Divided and this application March 13, 1942, Serial No. 434,521

1 Claim.

This invention relates to apparatus for making solder connections and may be used in carrying out a method of securing Wires or relatively fine gauge to metal surfaces formed on piezoelectric crystals described in my cop-ending application W. E. Ingerson, Serial No. filed May 8, 1941 (Patent No. 2,308,606, dated Jan. 19, 1943), and of which the present application is a division.

In practicing the method above mentioned a disc of solder of predetermined. size and form is made. The disc is picked up on the end of the wire and is placed at a required point on a metal surface formed on a piezoelectric crystal. The piezoelectric crystal is supported on a hot plate device and. is maintained at a required temperature. A heated tool is placed in contact with the disc of solder to make the disc form a solder connection between the wire and the metal surface on the crystal.

The present application covers the hot plate device used in making the solder connection.

In the drawings:

Fig. 1 is a view in perspective of the apparatus employed in making the solder connection, the apparatus parts being moi sted on a support in a convenient arrangement for use;

Fig. 2 is a top View of the hot plate device equipped with means adjustahly holding the crystal in required position;

Fig. 3 is a front elevational view of the shown in Fig. 2 and taken on the line Fig. 4 is a view, partly in section, taken on the line 4-5 in Fig. 2 and shows a thermostat provided in the hot plate device;

Fig. 5 is a side vi w in section. of the hot plate device taken on the line li-5 in Fig. 6 is a front View in sectic the hot plate device taken on the 1' 6 of Fig. 2;

Fig. 7 is a view in section of a portioi'i o the hot plate device taken on line 'l-l in Fig. 8 shows a fragmentary portion device with a wire held there solder picked up by the end of the w c,

Fig. 9 shows a portion of a crystal wih the wire solder-connected thereto; and

Fig. 10 is a top View of the part shown in Fig. 9. In solder-connecting a wire of relatively fine gauge to a metal surface provided. on a piezoelectric crystal, it is important that the wire be connected at the particular. y desired point on the crystal, also that the solder connection made is of a predetermined size and to in is sufficiently strong to permit use of the wire as a supporting means for the crystal. It is also important that the wire be not sufficiently affected by the heat applied in making the solder connection as to cause embrittlement or annealing of the wire and that the crystal be not subjected to reactive forces or thermal gradient-s suflicient to cause fracturin of the crystal.

The apparatus shown in the drawings is constructed and arranged to make solder connections in accordance with the method described in my oopending application W. E, Ingerson Serial No. 392,505, filed May 8, 1941 and as shown in Fig. 1 comprises a punch device 25, a chuck device 21, the hot plate device 23, the heated tool 29 and a reel support all of which are mounted on a suitable support 35. Th hot plate device 28 is shown as supporting a crystal 32. The wire 35 is held in the chuck device El so that the disc of solder on the end of the wire is in contact with the stripe 34 of metal on the crystal and the course of the heated tool 29 is shown by the dot dash line 33.

In practicing the method above mentioned a disc of solder of predetermined size and form is stamped out by of the punch device 25.

he crystal 32 with the metal stripe 34 thereon is placed on the hot plat device 23 and is adjusted on the hot plate device to a required position. An end portion of the wire 35 is threaded through jaws of the chuck device 2"! and so that a required length of the wire 35 projects below the jaws of the chuck device. A suitable flux is applied to the downwardly projecting end portion of the wire and this end portion of the wire is then brought into contact with a predetermined point on the metal stripe 3t and so that some of the flux will be eposited on the metal stripe 34. The chuck device 2'5 is then rotated to bring the downwardly projecting end of the wire in register with a receptacle provided in the punch device 255 contain the disc of solder. The end of the Wire 35 is thrust into the disc of solder so that the disc of solder is impaled on the wire. The chuck device is then rotated back to a posiover the crystal 3i. and the disc of solder is brought into engagement with the fiuxed portion of the metal stripe fit. The heated tool 29 is then rotated to bring the hot point 36, to which solder will not adhere, into contact with the disc of solder. The heat'frorn the tool melts the of solder so that the disc of solder will form a solder connection between the end or the wire and the metal stripe Since the end of the wire 35 was pr viously treated with a suitable flux, the molten material obtained by heating the disc of solder will have a tendency to flow upwardly along the wire 35 and will solidify on the end of the wire 35 in the form of a cone 3? when the heat is removed. The cone-shaped solder connection 31 obtained is shown in Fig, 9. Fig. 8 shows the disc 38 of solder on the end of the wire 35 before the disc is melted to obtain the solder connection 31. The hot plate device 28, the structure of which will be subsequently described, is equipped with heating means and is maintained at a temperature slightly below the melting point of the solder disc 38 so that the crystal 32 will be maintained at an elevated temperature during the making of the solder connection. This prevents fracturing the crystal 32 when the solder connection is being made. Maintaining the crystal at the elevated temperature reduces the reactionary effect upon application of the heated tool 29 to the disc 38 on the crystal 32. After the solder connection is made the wire 35 may be severed at a predetermined point to leave a portion of the wire solder-connected to the crystal as shown in Fig. 9. A suitable supply of wire 35 is contained on the spool 39 which is rotatably mounted on the reel support 30.

Hot plate device The hot plate device 28 is used to support the crystal 32 while an end of the wire 35 is being solder-connected to the stripe 34 on the crystal 32 and is provided with adjustable positioning means to move the crystal to its desired position and hold it in that position while the solder connecticn is being made.

As shown in Fig. 1 the hot plate device 28 is positioned within a relatively large rectangular opening 9'! provided in the support 3! and comprises a round table 98 and a rectangular frame plate 59, the upper surfaces of the table 98 and the plate 99 being in the same plane. The elongated aperture I is provided in the table 33 for a purpose to be later explained. As shown in Fig. 2 the table 98 is provided with cartridge type heating elements I'll which may be supplied with electrical current from a suitable source of supply, not shown, to heat the table 98 to a required temperature, the heating elements IIlI being located in apertures !32 provided in the table 58 as shown in Fig. 6.

The frame plate 99 as shown in Figs. 1, 3, and 6 is supported on spaced posts I53 and is secured thereto by means of the screws E04. The posts I03 are supported on spaced slide bars I35 and are secured thereto by means of the screws I05. The slide bars I65 rest on spaced tracks I0! which are cylindrical in cross section. The slide bars I35 are transversely grooved on their lower surfaces as shown at 138 to accommodate the tracks I07. The leaf springs I09 secured by mean of screws IIO to the under surface of the slide bars I are provided to retain the slide bars I05 on the tracks I01, the springs Hi3 having curved end portions to frictionally engage the under surfaces of the tracks Illl. The tracks I0! are longer than the aperture 9? in the support 3! and are secured at their ends by means of scr ws III as shown in Fig. 5, to cross pieces I I2. The bars 05 are apertured to accommodate the adjustment rod H3 X which is journaled in one of the crossbars I I2 and provided with retaining collars I I4 and I I5. The inner end of the rod H3 is externally threaded as shown at I I5 and one at least of the bars Ifl5 is internally threaded to receive the thread on the rod H3. The adjustment rod I13 is equipped with a manually operated knob IIl so that the adjustment rod I I3 may be manuall rotated.

The table 98 may be made of aluminum or other good heat transmitting material and rests iii on an insulating plate III! as shown in Fig. 6 which rests on the slide bars I05. The table 98 and the insulating plate I I8 are secured in place by means of screws IIS which extend through apertures in the slide bars I05, through suitable apertures in the insulating plate H8 and into threaded engagement with the table 98. The table 98 and the frame plate 39 may be moved backward and forward Within the aperture 91 by suitable rotation of the adjustment rod II3. It will therefore be seen that when the crystal 32 is supported on the table 98, the table 98 and the frame plate 99 may be moved as a whole either backward or forward within the aperture 81 to bring the crystal or a predetermined point thereon into a desired position relative to an end of the chuck device 21 when the chuck device 21 is swung into overlying position relative to the hot plate device 28. The hot plate device 28 is equipped with relatively long positioning finger I20, I2I to further adjust the crystal 32 to a required position and to hold the crystal in the position required. The fingers I and I2I are ar ranged in parallel spaced relation and extend across the upper surface of the table 98 and the frame plate 99 and may be moved toward each other to embrace the crystal 32, or away from each other by operation of a manually rotatable adjustment screw I22 equipped with a turning knob I23. Th screw I22 has right and left-hand thread portions engaging suitable threaded sleeves I24 and I25 which are slidably supported in a longitudinally apertured block I26. The block I26 is supported on flat bars I21 and I28 extending from the front edge of the frame plate 99 and which are secured to the under surface of the plate 99 by means of the screws I29. The bars I21 and I28 are secured by means of the screws I30 to the under surface of the block I25. A slide way I3I is provided in the rear wall of the block I23 to accommodate wide portions of the fingers I23 and I2I. The slide way I3I is in communication with the longitudinal bore I32 provided In the block I25. When the knob I23 is rotated in one direction the fingers I20 and I2I are moved toward each other by means of the threads on the shaft I22 and the sleeves I24 and I25, the widened ends of the fingers I20 and I2I being secured in suitable slots !33 provided in the sleeves I24 and I25 as shown in Fig. '7. Manual rotation of the knob I23 in the opposite direction will cause the fingers I20 and I2I to b moved away from each other. An elongated slot I34 is formed in the front portion of block I26 and screws I35 are provided in the block to regulate the frictional engagement of the upper and lower walls of the aperture I3I on the portions of the fingers I20 and I2I extending therethrough, the screws I35 being extended transversely across the slot I34 and having screw threaded engagement with the portion of the block I25 lying below the slot I34. When the screws I35 are tightened, the portions of the block I26 lying above and below the slot I34 are drawn toward each other. It will be seen that since the slot I34 extends almost to the bore I32 in the block I26, tigh ening of the screws I35 will have the effect of slightly widening the aperture I3I to allow the fingers I20 and I2I to more freely slide in the aperture I3I. The screws I35 may be used therefore to reduce or increase the frictional engagement of the walls defining the aperture I3I with the fingers I20 and I2I to a required extent. By tightening the screws I35 the fingers I20 and I2I be held in a required adjusted position.

The tracks I! are supported on spaced ties iii? and I37 and secured thereto by means of the screws I33. The ties I36 and I3! are secured by means of screws I39 to a flexible plate I40 supported at its ends on pillars MI and I42 and the plate I40 is held in spaced relation with the support 3| by means of the pillars I43 and I44. The pillars MI, M2, I43 and hi l are longitudinally bored and are held in place by long bolts I45 which also pass through the support 3|, the pillars, the flexible plate I40 and a rigid plate I46. It will be seen by looking at Fig. 3 that the rigid plate MB is suspended from the support .3I by means of the long bolts I45 which are equipped with nuts I47 to hold the parts in assembled condition. A bolt I48 is secured in about the central portion of the flexible plate I40 and extends downwardly through the rigid plate Md and is equipped with a relatively large knurled nut I40 to provide meansfor adjusting the table 98 and the frame plate 99 upward and downward relative to the support 3!. Turning of the nut I49 in a clockwise direction will cause downward flexing of the flexible plate I 40 and consequent slight lowering of the table 98 and the frame plate 99. When the nut I49 is turned in a counter-clockwise direction the flexible plate I40 will resume its normal position and will restore the table 98 and the frame plate 99 to normal position.

The aperture I00 provided in the table 98 as shown in Fig. 2 extends more than half the distance across the table 98 and through the entire thickness of the table. The upper edges of the walls defining the elongated aperture I00 are cut back to provide shoulders I50 to serve as a rest for a positioning block II through which a holding screw I52 extends. The lower end of the screw I52 as shown in Fig. 6 is provided with a large flat head I53 which extends in overlapping relation with the aperture I00 and into a slot I54 provided in the insulating plate H8. The upper end of the screw I52 is kerfed to permit turning the screw within the block I5I which may be adjusted along the aperture I00 to provide a backstop for the crystal 32. The aperture I00 also provides a space in which wires already attached to a crystal may extend While a Wire is being attached to the other side of the crystal.

A thermostat I55 is provided to control the supply r of current to the heating elements IN, the thermostat I55 being of the bimetallic element type and located in a suitable slot provided in the table 98. The thermostat I55 as shown in Fig. 4 may be adjusted by means of the screw I56 so that its contacts will open and close at required temperatures.

It will be seen that since the crystal may be held in a required position on the table 98 by means of the block I5I and the fingers I20 and till and the hot plate device may be adjusted forward and backward and may be raised and lowered the crystal may be readily brought to a required position relative to the wire held in the cl'zuclr device 2?. Also, that the pivotally supported heated tool 20 provides a ready and convenient means for applying heat to the disc of solder supported on the wire and engaging the stripe of metal on the crystal.

Heated tool The heated tool 29 as shown in Fig. l somewhat resembles an electric soldering iron. The hot point 35 of the tool, however, is made of aluminum or some other heat transmitting material to which solder will not adhere. The tool is held in a clamp it which is pivotally supported in the yoke I58. The yoke I53 is pivotally supported on a post I59 provided with a base I which is secured by means of the screws IBI to the support SI. A heating element in the tool may be supplied with current through a conductor I52 which may extend from a suitable source of current supply, not shown.

For an explanation of parts shown in the drawings and not specifically described in the present application reference may be had to my copending application W. E. Ingerson, Serial No. 392,505, filed lWay 8, 1941.

What is claimed is:

In a soldering apparatus of the type described, a hot plate device comprising a table adapted to support a crystal element, heating means in said table, a frame plate extending around said table and on an even plane with said table, spaced tracks, supporting means for said tracks, spaced bars riding on said tracks and supporting said table and said frame plate, means for adjustably moving said table and said frame plate along said tracks, a block supported along an edge of said frame plate, spaced fingers adjustably supported within said block and extending in parallel spaced relation across said table and said frame plate, screw threaded means supported within said block and arranged to move said fingers toward and away from each other, a flexible plate supporting said supporting means, a rigid plate extending in parallel spaced relation with said flexible plate, end supports for said flexible plate and said rigid plate and manually operated flexing means for said flexible plate, extending from said flexible plate and through said rigid plate and through operation of which said table and said frame plate may be raised and lowered.

WILLIAM E. INGERSON. 

